JPH11336256A - Reinforcement, manufacture of reinforcement and connecting structure of reinforcement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the connecting structure of a reinforcement, in which the strength of a connecting section is not lowered and the reinforcement can be joined simply in the reinforcement used for reinforced concrete, and the reinforcement used for the connecting structure and manufacture thereof. SOLUTION: The reinforcement consists of one reinforcement 1, in which a right male screw 3 is formed to the large diametral section 2 of an end section, another reinforcement 1, in which a left male screw 3' is formed to the large diametral section 2, and a joint element 4, in which a right female screw is notched at one end of both ends and a left female screw at the other end, and the end sections of both reinforcements are screwed while using the joint element 4 as a turnbuckle. Since the male screws 3, 3' are formed to the large diametral section, a bottom diameter is not made thinner than the reinforcement, and the strength of a connecting section is not lowered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reinforcing steel used for reinforced concrete, and further to a joint structure thereof.

[0002]

2. Description of the Related Art At a construction site, rebar is assembled before concrete is cast. The rebar used for this is
The length is fixed according to the standard, and at the construction site, the reinforcing bars are cut or connected according to the size of the structure and the length of the beams and columns. In this case, there is no problem in cutting, but joining is not easy.

[0003] Conventional methods of joining reinforcing bars include:
(1) After smoothing the end faces of the reinforcing bar to be joined, these smooth end faces are abutted with each other, the vicinity thereof is heated with a gas flame, and simultaneously, a compressive force is applied in the axial direction of the reinforcing bar to perform pressure welding, ( 2) A method in which a pipe is fitted into a connection portion of a reinforcing bar and molten iron is poured into the pipe, (3) A method in which a pipe is fitted into a connection portion of a reinforcing bar and an adhesive is poured into the pipe, (4) ) Method to cut the screw at the reinforcing bar joint and fasten with a turnbuckle, (5) Method to cut the taper screw at the reinforcing bar joint and fasten with a turnbuckle, (6) Attach an electrode to the reinforcing bar at the reinforcing bar joint and apply current. Sinking and crimping by electric welding, (7) fitting a pipe to the joint, crimping the fitted pipe, (8) fitting bamboo to the joint,
A method of holding down with metal fittings and the like are being implemented.

[0004]

However, as described in (1) above, the method of pressure contact requires the recruitment of experienced workers and requires a long working time. In addition, since a gas flame is used at a building site, there has been a problem that work efficiency is reduced in rainy weather. In addition, the method of pouring the melted iron of the above (2) is not possible without equipment for melting the iron, and (3)
Requires an adhesive and has to wait for the adhesive to solidify, which takes time. (4) In the case of joining with a turnbuckle, the valley portion of the external thread formed on the reinforcing bar side is thinner than the reinforcing bar, and the strength of the reinforcing bar is reduced. When the tapered screw of (5) is used, in addition to the problem of (4), the diameter at the tip of the tapered portion is further reduced.
Strength reduction is weighted. The methods (7) and (8) are troublesome and vary depending on the skill of the operator.
It is difficult to secure stable joint strength. Also, (1),
When the connection portion is heated by electricity or gas flame as in (2) or (6) electric welding, there is a problem that the vicinity of the heated portion of the reinforcing bar becomes weak.

The present invention has been conceived in view of the above facts. The present invention has been made in consideration of the above circumstances, and it is an object of the present invention to provide a joining structure of a reinforcing bar which does not decrease the strength of a joining portion and which can be easily joined. It is intended to provide a manufacturing method thereof.

[0006]

Means for Solving the Problems To achieve the above object, a reinforcing bar according to the present invention is characterized in that a large diameter portion is formed in a part of the reinforcing bar. Further, a configuration in which the large diameter portion is formed at an end of a reinforcing bar, or a configuration in which a male screw is engraved in the large diameter portion can be adopted.

[0007] A method of manufacturing a reinforcing bar according to the present invention is characterized in that a build-up member is applied to a part of the reinforcing bar, and a large-diameter portion is formed by being press-bonded to the reinforcing bar by cold forging.

In the joint structure of a reinforcing bar according to the present invention, a large-diameter portion is formed at each end of a plurality of reinforcing bars, and a male screw is engraved on the large-diameter portion so that each end is formed into one joint. It is characterized by being screwed into each of a plurality of female screws.

[0009] Alternatively, while having a large diameter portion at the end,
One rebar having a right male thread engraved on the large diameter portion, another rebar having a large diameter portion at the end and a left male thread engraved on the large diameter portion, and a right rebar having one end at both ends. Female screw, a connector having a left female screw engraved at the other end, and a right male screw of the above-mentioned rebar is screwed into a right female screw of the connector, and a female screw on the left of the connector is formed. It is characterized in that the left external thread of the other reinforcing bar is screwed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A to 1D are views showing a state until a joint structure of the present invention is formed from a reinforcing bar. The reinforcing bar 1 shown in these figures is a solid round bar. In order to improve the connection with concrete, substantially semicircular projections 1a are formed at equal intervals on the upper and lower sides of the figure, and the upper and lower projections are formed. And are shifted by half a pitch.

At the end of the reinforcing bar 1, a large diameter portion 2 is formed as shown in FIG. The large-diameter portion 2 is a flat cylindrical surface, and a method for forming the large-diameter portion 2 will be described with reference to FIGS.

After the large diameter portion 2 is formed, external threads 3, 3 'are engraved on the surface as shown in FIG. The external threads 3, 3 'can be easily formed at the work site using a die or the like. If one external thread 3 is a right-hand thread, the other external thread 3 'is a left-hand thread.

When the left and right external threads 3, 3 'are engraved,
As shown in (d), these are screwed into female screws on both sides of the turnbuckle 4 as a connector, and tightening is completed. The turnbuckle 4 is a hexagonal prism in the illustrated example, but if it is a quadratic prism or an octagonal prism, it can be turned with a spanner or the like and can be tightened with a strong force. Alternatively, a hole may be formed in the center of the turnbuckle, and a rod may be inserted into the hole and rotated.

According to this embodiment, since the external threads 3 and 3 'are engraved on the large diameter portion 2, the root diameter of the external thread can be made larger than that of the reinforcing bar 1. Can be prevented from becoming thinner than the diameter of the reinforcing bar 1 and reducing the strength.

Further, the thread cutting of the external thread can be sufficiently performed even at a construction work site with a die, and the operation is simple, so that a skilled person is not required. Although the large diameter portion 2 is formed at the end of the reinforcing bar 1, it is formed in the middle of the reinforcing bar 1 and cut at the end of the large diameter portion 2 or at the center of the large diameter portion 2 at a work site. Is also good. The cutting operation in that case is the same as cutting the rebar, and is a relatively simple operation.

FIG. 2 shows various connectors including the above-mentioned turnbuckle. (A) is a perspective view of the turnbuckle 4 used in the embodiment of FIG. Although only one female screw 4a is shown, the other female screw is engraved in the opposite direction. When connecting two reinforcing bars at an angle such as a right angle, an elbow-shaped connector 5 as shown in FIG. 2B may be used. In this case, the female screws 5a on both sides of the connector 5
Can be both right-handed screws. The angle is not limited to 90 degrees as shown, but can be any angle. FIG.
As shown in (c), a T-shaped connector 6 can be used.
Also in this case, all the female screws 6a may be right-handed screws.

FIGS. 3 and 4 are views for explaining a method of forming the large diameter portion 2 on the reinforcing bar 1. FIG. As a method of forming the large-diameter portion 2, a method of building up by electric welding or gas welding can be considered, but it is not suitable for mass production because it takes a lot of trouble.
Therefore, in the present invention, cold working is performed by a horizontal hydraulic press.

The horizontal hydraulic press shown in FIG. 3 has a fixed die 11 on the right side of the drawing and a movable die 12 on the left side. A die 13 is attached to the fixed mold 11 and the movable mold 1 is mounted.
A punch 14 is attached to 2. Both the die 13 and the punch 14 have hollow portions, into which the reinforcing bar 1 is inserted. The diameter of the hollow portion of the die 13 is larger than that of the punch 14, into which a pipe-shaped overlay member 15 has been inserted in advance, and the reinforcing bar inserted from the punch 14 side When the front end of the mold 11 advances through the hollow portion and comes into contact with the surface of the fixed mold 11, the mold is stopped. That is, positioning is performed here.

The tip of the punch 14 is tapered, and the punch side of the die 13 is widened so that the tip of the punch 14 can enter. When the movable mold 12 advances toward the fixed mold 11 from the state shown in FIG. 3, the tip of the punch 14 enters into the hollow portion of the die 13 and the build-up member 15
When the die 14 is completely inserted into the punch as shown in FIG.
It is deformed so as to spread in the space between the two, and is pressed into contact with the rebar 1 to form a large diameter portion 2.

When the movable mold 12 returns to the state shown in FIG. 3 from the state shown in FIG. 4, the projecting bar 16 provided on the fixed mold 11 moves in the direction of the arrow to discharge the reinforcing bar 1 out of the punch 14. Since the above-mentioned press working is performed as cold working without heating, there is almost no residual stress due to heat in the reinforcing bar 1 and the large-diameter portion 2, and the strength does not decrease. In addition, the outer surface of the large diameter portion 2 is also smooth like the inner surface of the die 13, and there is no need for finishing.

According to an embodiment of the present invention, in a factory,
If various joints such as turnbuckles are made at the same time as forming a large diameter part on the reinforcing bar, at the construction site, the reinforcing bar is cut to the required length, an external thread is engraved with a die, etc. It is only necessary to screw them together, so that only the work on site is simple, and no skilled worker is required. The work in the factory is also the formation of a large-diameter portion by cold working and the manufacture of a connector, which enables mass production and cost reduction.

[0022]

As described above, the reinforcing bar of the present invention
Since the large diameter part is formed in a part of the rebar, the male screw can be easily engraved on the construction site.Moreover, since the male screw is engraved on the large diameter part, the root diameter does not become thinner than the rebar, Does not reduce strength. When the large diameter portion is formed at the end of the rebar, a part of the cutting work on site can be omitted,
Work becomes easier.

If a large-diameter portion is formed by cold forging by applying a build-up member to a part of a reinforcing bar, it is possible to prevent the large-diameter portion from decreasing in strength due to heating. A configuration in which a large diameter portion is formed at each end of the plurality of rebars, a male screw is engraved on the large diameter portion, and each end is screwed to each of the plurality of female screws formed in one joint. If it does, a joining structure without a strength fall with a simple structure can be obtained. Also, the work is simple.

A reinforcing bar having a large-diameter portion at the end and a right male screw formed at the large-diameter portion, and a left male screw having a large-diameter portion at the end portion and a large-diameter portion formed at the end. And a connector having a right female screw at one end of both ends and a left female screw at the other end, and the right female screw of the above-mentioned one reinforcing bar is attached to the right female screw of the connector. If the male screw is screwed and the left male screw of the above-mentioned other rebar is screwed to the female screw on the left side of the joint, a simple structure and simple work can be used to make the joint structure of the rebar with no strength reduction. Obtainable.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a procedure for forming a joint structure of a reinforcing bar according to the present invention.

FIG. 2 is a perspective view showing various connectors.

FIG. 3 is a diagram illustrating a method of forming a large diameter portion of a reinforcing bar according to the present invention.

FIG. 4 is a diagram illustrating a method of forming a large diameter portion of a reinforcing bar according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Reinforcing bar 2 Large diameter part 3,3 'male screw 4,5,6 Connector 15 Overlay member

Claims (6)

[Claims] 1. A rebar having a large diameter portion formed in a part of the rebar. 2. The reinforcing bar according to claim 1, wherein the large diameter portion is formed at an end of the reinforcing bar. 3. The reinforcing bar according to claim 1, wherein a male screw is formed in the large diameter portion. 4. A method for manufacturing a reinforcing bar, wherein a build-up member is applied to a part of the reinforcing bar and a large diameter portion is formed by press-fitting the reinforcing bar by cold forging. 5. A large-diameter portion is formed at each end of a plurality of reinforcing bars, and a male screw is engraved on the large-diameter portion, and each end is formed on each of a plurality of female screws formed on one joint. A rebar joint structure characterized by being screwed together. 6. A reinforcing bar having a large-diameter portion at an end and a right male screw engraved on the large-diameter portion, and a left male screw having a large-diameter portion at the end and a large-diameter portion at the end. And a connector with a right female screw at one end of both ends and a left female screw at the other end. The right female screw of the connector has A joint structure of a reinforcing bar, wherein a right male screw is screwed in, and a left male screw of the other reinforcing bar is screwed into a left female screw of the connector.